| Abstract: | The kinetics of the reaction between nitric oxide and chlorine have been investigated in both carbon tetrachloride and glacial acetic acid. The nitric oxide-oxygen reaction has been investigated in carbon tetrachloride. The appearance of product, NOCl or NO2, was monitored spectrophotometrically at a wavelength of 475 nm for NOCl and 343 nm for NO2. These measurements were performed using an Amino-Morrow stopped-flow apparatus equipped with a Beckman D U monochromator. The data for both the NO? Cl2 and NO? O2 systems could be fitted to the third-order integrated equation and the calculated rate constants were 2.75 × 103 M?2 s?1 and 2.79 × 106 M2 s?1, respectively, at 25.1°C. There was a noted increase in rate constants on changing the solvent from carbon tetrachloride to acetic acid. The likelihood of a termolecular encounter is inherent in the mechanism, however, no real evidence to substantiate either a direct termolecular or a series of two bimolecular steps has been obtained, although a ?7 kcal for ΔH0 would support the latter. |
